Layer | Fill | Outline |
---|
Map layers
Theme | Visible | Selectable | Appearance | Zoom Range (now: 0) |
---|
Fill | Stroke |
---|---|
Collaborating Authors
Results
Abstract Pressure maintenance support in mature fields where permeability heterogeneity is present requires proper distribution of injected water into the respective zones of interest. This process can be extremely challenging, if no method for allocating the proper amount of water into each zone is available. An operator in the South China Sea, who had initiated a water injection project using legacy single-string two-zone completion technologies, found himself in this predicament, since no selective control for pressure maintenance had been considered for the project. During the past few years, the application of intelligent completion (IC) technology has increased rapidly. This acceptance has been due primarily to its proven capabilities for reservoir monitoring and corresponding optimization of well performance without well interventions. Historically, the majority of IC applications have been in production wells; however, an increasing number of operators have started adopting IC technology for their injector wells. This paper presents a case study in which IC technology was successfully applied in an offshore field in the South China Sea to provide an efficient water-injection method for optimizing pressure support as well as sweep. The operator selected this technology, as it presented a solution for optimizing the water injection. In addition to eliminating problems experienced with the incapability of the legacy completion technology to monitor water allocation and pressure maintenance for each zone, the IC technology would allow selective well testing for each zone. By evaluating the reservoir properties and characteristics of each zone independently, an intelligent completion would provide another key benefit to the operator, since it would comply with the platform size restrictions for the pumping equipment. The paper will discuss field objectives, the conceptual design, the design obstacles, and the operational challenges experienced during the job execution.
- Well Completion > Completion Selection and Design > Completion equipment (1.00)
- Well Completion > Completion Monitoring Systems/Intelligent Wells (1.00)
- Reservoir Description and Dynamics > Improved and Enhanced Recovery > Waterflooding (1.00)
Abstract A sour carbonate reservoir has been identified for water flooding to improve hydrocarbon recovery. The field is situated in the South of Oman and was discovered by PDO in 2005. Production began in 2007 and contains crude oil with 30° API oil gravity and solution GOR of 80 Sm/m, as well as, sour fluid contaminants of 5 mol% H2S and 3 mol% CO2. Reservoir water fluid samples confirm salinity is more than 220,000 mg/L chloride ions. While the reservoir is over-pressured at more than 600 bara with a bubble-point pressure of 140 bara, reservoir pressure continues to decline during the initial depletion phase of the field development. Although water flooding will arrest pressure decline in the reservoir, due to subsurface challenges and uncertainties, artificial-lift is considered a key project requirement during the expected field life. Initially, reservoir water salinity is expected to contribute to an increased risk of salt precipitation and related flow assurance concerns as the water flood approaches the production wells. In addition, expected producing conditions are considered to be extremely corrosive. This paper will provide a summary of the expected field conditions, water flood project background and key artificial-lift application challenges including the proposed conceptual well completion designs to support the field development. A summary of artificial-lift selection, design and implementation strategy will be explained including objectives, scope and results of the recent jet-pump field trial. Finally, a brief summary of the key conclusions and plans forward will be shared.
- North America > United States (1.00)
- Asia > Middle East > Oman (0.62)
- Energy > Oil & Gas > Upstream (1.00)
- Water & Waste Management > Water Management > Lifecycle > Disposal/Injection (0.48)
- Well Completion > Completion Installation and Operations (1.00)
- Reservoir Description and Dynamics > Improved and Enhanced Recovery > Waterflooding (1.00)
- Production and Well Operations > Artificial Lift Systems (1.00)
Fracture Growth Monitoring in Polymer Injectors- Field Examples
Shuaili, Khalfan (Petroleum Development Oman LLC) | Cherukupalli, Pradeep Kumar (Petroleum Development Oman LLC) | Al-Saadi, Faisal Salim (Petroleum Development Oman LLC) | Hashmi, Khalid Al (Petroleum Development Oman LLC) | Jaspers, Henri F (Petroleum Development Oman LLC) | Sen, Subrata (Shell International Exploration and Production Investments B.V)
Abstract The objective of injecting polymer in brown fields is to increase recovery beyond primary and secondary recovery mechanisms. However, generally it is difficult to achieve adequate (viscous) polymer injectivity in depleted sandstone reservoirs without fracturing. Therefore, monitoring fracture propagation is required in order to control vertical conformance and areal sweep and avoid early polymer breakthrough. Different surveillance methods are used to identify the existence and properties of fractures in polymer injectors. Pressure Fall off (PFO) survey data in conjunction with time-lapse temperature surveys are extensively used to determine the fracture dimensions. PFO tests in Polymer injectors have particular characteristics since they are influenced by shear-dependent viscosity seen in non-Newtonian fluids. A specially developed Injection Fall-off (IFO) model was used to determine fracture dimensions which is based on exact semi-analytical solution to the fully transient elliptical fluid flow equation around a closing dynamic fracture developed by Shell, (Van den Hoek 2005), as static fracture models are inadequate. This paper presents different phenomena in polymer injection seen in PFO tests such as fracture closure, the effect in-situ polymer rheology and the detection of the polymer front. The paper demonstrates the effect of liquid-level drop observed in PFO survey in under-pressured reservoirs and its impact on determining fracture and some other reservoir properties. It also shows how plot-overlays of time lapse PFO's for a particular well can be used to track changes in fracture dimensions. All of these are illustrated by a number of field examples of polymer PFO which also demonstrate the calculated fracture dimensions from the data. Finally, some recommended best practices are suggested for fracture monitoring.
- Geology > Geological Subdiscipline > Geomechanics (1.00)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Sandstone (0.55)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Improved and Enhanced Recovery > Waterflooding (1.00)
- Reservoir Description and Dynamics > Improved and Enhanced Recovery > Chemical flooding methods (1.00)
- (2 more...)
Saudi Arabia's Two World Records for Aided Coiled Tubing Reach and Real Time Logging in Extended Reach Well
O. Arukhe, James (Saudi Aramco) | A. Dhufairi, Mubarak (Saudi Aramco) | A. Ghamdi, Saleh (Saudi Aramco) | Duthie, Laurie (Saudi Aramco) | Yatem, Karam (Saudi Aramco) | Elsherif, Tamer (Schlumberger) | Ahmed, Danish (Schlumberger)
Abstract Two new records exist in one of current world's largest oil increment field development projects in Saudi Arabia. The records set while achieving a well's intervention objectives include; 1. Attaining the deepest coiled tubing (CT) reach for rigless well intervention at 29,897 ft (9.11 km) measured depth in an extended reach open hole horizontal power injector well using a CT tractor and; 2. The first application of real time logging enabled through a wired motor head assembly via the tractor. The intervention objectives were to acid stimulate an open hole completed relatively deep in the reservoir with total depth of 29,897 feet and open hole length of 6,697 feet utilizing 2′ CT with open hole tractor, to perform injectivity / falloff test, and to conduct real time logging for evaluating the reservoir's injectivity profile. The paper examines several challenges that engineers and operators encountered during intervention in this well. A partially sealing high viscosity tar layer exists between the overlaying oil column and underlying aquifer. Operationally, the challenge was to overcome obstructions arising from tar accumulation during the well intervention. This challenge was overcome by the use of a solvent and the well was successfully acidized with the aid of the CT-tractor. The other concern was the tractor integrity while large amount of acid is pumped and the extended exposure time of tractor to acid. The tractor successfully handled huge amounts of corrosive fluids in a sour environment while providing the required pulling force to reach the total depth of the well to set the intervention record for tractor reach without adverse effects on the integrity of its O-rings, seals, and mechanical parts. In addition to organic deposits, azimuth changes in the well added to well entry challenges as a result of changes in hole inclination, doglegs, and azimuth. The application of real time informed decisions was critical in overcoming all the challenges, optimizing stimulation design, and yielding a notable and consistent injectivity increase with evidence of extended life and a true reflection of deep penetration into the damage zone. The successful re-entry will benefit industry operators confronting similar intervention challenges.
- Asia > Middle East > Saudi Arabia > Saudi Arabia - Kuwait Neutral Zone ("Partitioned Zone") > Arabian Basin > Widyan Basin > Wafra Joint Operations Block > South Umm Gudair Field > Pre-Khuff Formation (0.99)
- Asia > Middle East > Saudi Arabia > Saudi Arabia - Kuwait Neutral Zone ("Partitioned Zone") > Arabian Basin > Widyan Basin > Wafra Joint Operations Block > South Umm Gudair Field > Khuff Formation (0.99)
- Well Drilling > Drilling Operations > Directional drilling (1.00)
- Well Completion > Completion Installation and Operations > Coiled tubing operations (1.00)
- Reservoir Description and Dynamics > Improved and Enhanced Recovery > Waterflooding (1.00)
- (3 more...)
- Information Technology > Artificial Intelligence > Robots (1.00)
- Information Technology > Architecture > Real Time Systems (1.00)
Abstract In many oilfields the relatively small number of high-cost, highly productive wells, coupled with a carbonate and or sulfate scaling tendency (upon waterflood breakthrough of injected seawater) requires effective scale management along with removal of near-wellbore damage in order to achieve high hydrocarbon recovery. The nature of the well completion strategy in new fields such as frac packs for sand control and acid stimulation for carbonate reservoirs had resulted in some wells with higher than expected skin values due to drilling fluid losses, residual frac gel, fluid loss agents, and fines mobilization within the frac packs where applied. The paper will present how the challenges of managing impaired completions and inorganic scale forced innovation in terms of when to apply both stimulation and scale inhibitor packages to sandstone and carbonate reservoirs. This paper will outline a novel process for non-conventional batch chemical applications where bullhead stimulation treatments have been displaced deep into the formation (<20ft) using a scale inhibitor overflush. Not only does this benefit the stimulation by displacing the spent acid and reagents away from the immediate wellbore area, but the combined treatment provides cost savings with a single mobilization for the combined treatment. The paper will describe the laboratory testing that was performed to qualify the treatments for both sandstone and an HP/HT gas condensate carbonate reservoir. The lessons learned fromcarbonate corefloodevaluationunder HT/HP conditions when appling stimulation fluids with and without scale inhibitor present in the treatment stageswill be presented. Many similar fields are currently being developed in offshore Brazil, West Africa and Middle East, and this paper is a good example of best-practice sharing from another oil basin.
- Asia > Middle East (0.69)
- Africa (0.68)
- Europe > United Kingdom > North Sea > Central North Sea (0.28)
- Water & Waste Management > Water Management > Constituents > Salts/Sulphates/Scales (1.00)
- Energy > Oil & Gas > Upstream (1.00)
- Europe > United Kingdom > North Sea > Central North Sea > Moray Firth > Moray Firth Basin > Moray Firth Basin > Witch Ground Graben > P.213 > Block 16/26a > Brae Field > Alba Field > Caran Sandstone Formation (0.99)
- Europe > United Kingdom > North Sea > Central North Sea > Moray Firth > Moray Firth Basin > Moray Firth Basin > Witch Ground Graben > P.213 > Block 16/26a > Brae Field > Alba Field > Alba Sandstone Formation (0.99)
- Europe > United Kingdom > North Sea > Central North Sea > Moray Firth > Moray Firth Basin > Fladen Ground Spur > Witch Ground Graben > P.213 > Block 16/26a > Brae Field > Alba Field > Caran Sandstone Formation (0.99)
- (4 more...)
- Well Completion > Sand Control > Frac and pack (1.00)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs (1.00)
- Reservoir Description and Dynamics > Improved and Enhanced Recovery > Waterflooding (1.00)
- (3 more...)
Abstract Modern horizontal well completion technologies consisting of cased or openhole wellbores and multiple hydraulic fractures have revolutionized production from very low permeability oil and gas reservoirs. This paper extends the application of these completions to production systems using thermal Enhanced Oil Recovery (EOR) processes. It reports the results of an extensive simulation study to evaluate the performance of different completion technologies using horizontal wells with and without multiple hydraulic fractures. The results indicate that combination of horizontal wells with multiple fractures increases access to the reservoir and enhances fluid injectivity, improves sweep efficiency and time, accelerates oil production rates and increases ultimate oil recovery. Proposed production system is especially beneficial in reservoirs with high heterogeneity in fluid and rock properties. It lowers the risk of injected fluid channeling through high permeability segments and natural fractures; thereby improving the injection profile and reducing by-passing of the reservoir fluid. In addition, the paper provides completion recommendations for avoiding some of the operational issues that usually come up when considering horizontal wells, and, hydraulic fracturing for EOR systems.
- Europe (1.00)
- Asia (0.93)
- North America > United States > Texas (0.69)
- (2 more...)
- North America > United States > Texas > Permian Basin > Yeso Formation (0.99)
- North America > United States > Texas > Permian Basin > Yates Formation (0.99)
- North America > United States > Texas > Permian Basin > Wolfcamp Formation (0.99)
- (23 more...)
- Well Drilling > Drilling Operations > Directional drilling (1.00)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Reservoir Fluid Dynamics > Flow in porous media (1.00)
- Reservoir Description and Dynamics > Improved and Enhanced Recovery > Waterflooding (1.00)
Abstract Restricted flow capacity of low permeability oil formations imposes unique challenges to the implementation of CO2-WAG processes in such reservoirs. Application of multi-stage fractured horizontal wells can substantially improve the injection and production rates. However, there are various design parameters and operating conditions which can affect the performance of a WAG flood. The parameters considered in this study are those related to development pattern (well spacing and well completion strategy), hydraulic fracture geometry (half-length and spacing), WAG parameters (WAG ratio and CO2 slug size) and the timing of the switch from primary or water-flood to WAG scheme. In this study, CO2 EOR performance is assessed based on the oil recovery factor and also the amount of stored CO2; in other words, the objective is to achieve both the goals of enhanced oil recovery and sequestration of CO2 in the tight oil formation. However, to reflect the effect of time, the net present value (NPV) of the projects was also considered. All three of these parameters were therefore included in objective functions to be optimized. The effect of all aforementioned parameters on objective functions was investigated using a compositional simulator. Design of experiment (DOE) was then utilized to perform a comprehensive statistical analysis to recognize the most prominent factors in fulfillment of each objective function in a tight reservoir with properties similar to Pembina Cardium field. Response surfaces were generated to quantify the effect of the factors on the objective functions. Optimization was carried out to find those sets of factors which provided the highest recovery, storage, and NPV. Searching for optimal values can be extended to any combination of objective functions which are obtained by applying weighting multipliers to each individual objective function.
- North America > Canada > Alberta (0.49)
- North America > United States > Texas > Dallas County (0.28)
Analysis of Flow and the Presence of Fractures and Hot Streaks in Waterflood Field Cases
Baker, Richard (Baker Hughes RDS) | Stephenson, Tim (Gaffney Cline & Associate) | Lok, Crystal (Gaffney Cline & Associate) | Radovic, Predrag (Gaffney Cline & Associate) | Jobling, Robert (Gaffney Cline & Associate) | McBurney, Cameron (Gaffney Cline & Associate)
Abstract Over a thousand well pairs in five different fields in Western Canada have been examined using communication analysis techniques. The results of this analysis strongly suggest that in addition to conventional Darcy type flow through the matrix rock, there is also strong communication between wells through induced fractures, and/or natural fractures. Most of these five fields are not typically thought of as naturally fractured. Nonetheless this type of fracture flow exists. It is highly likely that these hot streaks are pressure sensitive and therefore have a geo-mechanical component that controls permeability. The geo-mechanical component means that permeability can vary with time and injection pressure. This work on the Western Canadian Sedimentary Basin (WCSB) is similar to work done by Heffer in the North Sea.
- North America > Canada > Alberta (0.87)
- North America > United States > Texas (0.69)
- North America > Canada > Saskatchewan (0.68)
- (3 more...)
- North America > Canada > Saskatchewan > Western Canada Sedimentary Basin > Alberta Basin (0.99)
- North America > Canada > Northwest Territories > Western Canada Sedimentary Basin > Alberta Basin (0.99)
- North America > Canada > Manitoba > Western Canada Sedimentary Basin > Alberta Basin (0.99)
- (5 more...)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization (1.00)
- (2 more...)
Residual Oil Saturation Determination for EOR Projects in Means Field, a Mature West Texas Carbonate Field
Pathak, Prabodh (ExxonMobil Production Company) | Fitz, Dale E. (ExxonMobil Exploration Company) | Babcock, Kenneth P. (ExxonMobil Production Company) | Wachtman, Richard J. (ExxonMobil Production Company)
Summary The technical success of an enhanced oil recovery (EOR) project depends on two main factors: first, the reservoir remaining oil saturation (ROS) after primary and secondary operations, and second, the recovery efficiency of the EOR process in mobilizing the ROS. These two interrelated parameters must be estimated before embarking on a time-consuming and costly process for designing and implementing an EOR process. The oil saturation can vary areally and vertically within the reservoir, and the distribution of the ROS will determine the success of the EOR injectants in mobilizing the remaining oil. There are many methods for determining the oil saturation (Chang et al. 1988; Pathak et al. 1989), and these include core analysis, well-log analysis, log/inject/log (LIL) procedures (Richardson et al. 1973; Reedy 1984), and single-well chemical tracer tests (SWCTT) (Deans and Carlisle 1986). These methods have different depths of investigation and different accuracies, and they all provide valuable information about the distribution of ROS. No single method achieves the best estimate of ROS, and a combination of all these methods is essential in developing a holistic picture of oil saturation and in assessing whether the oil in place (OIP) is large enough to justify the application of an EOR process. As Teletzke et al. (2010) have shown, EOR implementation is a complex process, and a staged, disciplined approach to identifying the key uncertainties and acquiring data for alleviating the uncertainties is essential. The largest uncertainty in some cases is the ROS in the reservoir. This paper presents the results from a fieldwide data acquisition program conducted in a west Texas carbonate reservoir to estimate ROS as part of an EOR project assessment. The Means field in west Texas has been producing for more than the past 75 years, and the producing mechanisms have included primary recovery, secondary waterflooding, and the application of a CO2 EOR process. The Means field is an excellent example of how the productive life and oil recovery can be increased by the application of new technology. The Means story is one of judicious application of appropriate EOR technology to the sustained development of a mature asset. The Means field is currently being evaluated for further expansion of the EOR process, and it was imperative to evaluate the oil saturation in the lower, previously undeveloped zones. This paper briefly outlines the production history, reservoir description, and reservoir management of the Means field, but this paper concentrates on the residual oil zone (ROZ) that underlies the main producing zone (MPZ) and describes a recent data acquisition program to evaluate the oil saturation in the ROZ. We discuss three major methods for evaluating the ROS: core analysis, LIL tests, and SWCTT tests.
- Geology > Rock Type > Sedimentary Rock > Carbonate Rock (0.93)
- Geology > Geological Subdiscipline (0.67)
- North America > United States > Texas > Permian Basin > Yeso Formation (0.99)
- North America > United States > Texas > Permian Basin > Yates Formation (0.99)
- North America > United States > Texas > Permian Basin > Wolfcamp Formation (0.99)
- (26 more...)
- Reservoir Description and Dynamics > Reservoir Fluid Dynamics > Flow in porous media (1.00)
- Reservoir Description and Dynamics > Improved and Enhanced Recovery > Waterflooding (1.00)
- Reservoir Description and Dynamics > Improved and Enhanced Recovery > Reduction of residual oil saturation (1.00)
- (6 more...)
Abstract The world's first successful application of a wired motor head assembly to allow real time logging with a tractor in an extended reach open hole horizontal well has been recorded in Saudi Arabia. The well, located on one of two finger islands, was completed to a total depth of 29,897 ft. (9.11 km) MD; making it the deepest well with open-hole section in the field development, and outside of the reach of traditional tapered coiled tubing (CT) used for well intervention. Using 2 inch tapered coil tubing and well tractor, the well was successfully acid-stimulated in 14 stages with a total of 3,850 barrels of (diesel) emulsified HCl acid recipe. This paper shows that although tractor interventions have a proven record and are the preferred deployment method for extended well stimulation, there still existed the uncertainty of conducting real time production logging while simultaneously tractoring. This additional challenge in the industry could be overcome by utilizing real time Electrical to Optical (EtO) production logging measurements simultaneously with the running of a tractor. A comparison of the pre- and post-stimulation injectivity indices on a separate run prior to the real time production log acquisition showed an eight fold injectivity index improvement from 53 bpd/psi to 400 bpd/psi. The resulting marked injectivity improvement from acid stimulation also showed the benefit of informed decisions from real time fiber-optic distributed temperature system (DTS) in fluid placement. Practical applications of these outcomes include the acquisition of real time data of comparable quality with conventional e-line tools resulting in distinct technical and economic advantages in the development of the remaining parts of the field. Others include the reduction in total well delivery costs from an ability to accurately evaluate well performanceand diagnose problems in real time. The ability to employ real time information to effectively stimulate extended reach wells provide assurance that stimulation can serve as a technical and an economic solution for addressing the relatively high skin damage problem post drilling and completion. Real time logging with the tractor is logistically efficient and allows real time acquisition of injection profiles with the possibility for improving data quality with return passes.
- Well Drilling > Drilling Operations > Directional drilling (1.00)
- Well Completion > Completion Installation and Operations (1.00)
- Reservoir Description and Dynamics > Improved and Enhanced Recovery > Waterflooding (1.00)
- (2 more...)